Raheem Sterling returns to Liverpool training as the 'most valuable young player in Europe'

Manchester City are hot on the heels of the unhappy youngster

(Getty Images)

Raheem Sterling returned to Liverpool training on Monday rated as the 'most valuable young player in Europe'.

The 20-year-old is unhappy at Anfield and a prime target for Premier League rivals Manchester City, who had a £40million bid rejected last week.

With Liverpool heading to Bangkok on Sunday for their pre-season tour, City will want to try and wrap up business this week, otherwise his potential move will have to be put on hold until the Reds return in early August.

Sterling has been rated the most valuable youngster in Europe, and given a weighted value of £35m, after a study by the Soccerex 20 Football Value Index.

The winger is one of four English players in the top 20, along with Luke Shaw, John Stones and Calum Chambers, with the study analysing all players under 21 that play in Europe. The study factors in age, position, club, contract length, market value perception, international caps, goals, injuries and technique.

"Combining all the factors, we came up with Sterling as the most valuable," the study's author Esteve Calzada said.

Nine of the top 20, including Manchester United new boy Memphis Depay, will ply their trade in the Premier League next season.

"That shows the strength of the competition," Calzada added.

"We are used to seeing high-value domestic-only transfers in the UK. This is just another way to prove that."